Some orthopedic procedures require a screw or peg to be inserted into bone in order to hold fragments together, or to hold bones in alignment to permit fusion. It is a disadvantage when the screw head projects beyond the bone surface at the insertion site. However, it is also an advantage for the screw to have a head of a sufficient size to allow sufficient torque to be applied to the screw to allow it to be easily implanted in the bone. The present invention address that issue by providing a countersink, and a drill designed specifically to provide a countersink in the cortical bone at the implantation site so that a round headed screw or peg will not remain proud or project too far beyond the surface of the bone.